Quest Studios released a few MIDIs, but LEC told them to take it down. They were available on a few other websites though, but the sites seem to be gone now. You could use Scummrev over at http://scumm.mixnmojo.com (under Utilities) to extract the MIDIs and edit them into complete tracks, though.

I recorded the SoMI MIDI files when I did the original digital audio recording of the soundtrack, so they were easy to put up.

For MI2, I edited them from scratch into different tracks, and they require two MT-32s daisy chained plus the right sysex bank before you can play them back. Converting them to General MIDI would take forever and I'm never satisfied with the results..

That would be me... but I don't like beer, so I'll just take the bottle deposit.

BTW: That Largo Theme was made by the guys from HighLand Productions (Andrew Langley and Jimmi Thøgersen) for Mojo's MI5 April Fool's joke, while the medley was made by some fans (credited as Matt Johnson, Tom Woodrow and PH).